Means for insulating electric conductors.



No. 838,764. PATENTED DEC. 18, 1906.

- S. BERGER.

MEANS FOR INSULATING ELECTRIC GONDUCTORS.

, APPLIUATION FILED MAY 9.1905.

ya gym/h W2? THE NORRIS PETE 'roN.

UNITED STATES PATENT OFFICE. I

STANISLAUS BERGER,

MEANS FOR INSULATING OF 'IRIER, GERMANY.

ELECTRIC CONDUCTORS.

Specification of Letters Patent. 7

Patented Dec. 18, 1906.

To all whom it THIN/Z] con/001%."

Be it known that I, STA vIsLAUS BERGER, a subject of the King of Prussia, German Emperor, residing at Trier, in the Kingdom of Prussia and German Empire, have invented new and useful Improved Means for and Methods of Insulating Electric Conductors, of which the following is a specification.

For electric light and power conductors the usual practice is to lay covered wires insulated with gutta-percha or to place such wires in armored pipes or to employ special cables.

The disadvantage of the first method is that there is no safety afforded against fire, shortcircuiting, and grounding, water, acios, and external influences, and such-wires are wholly unsuited for high tension currents. The same drawbacks attach to the use of armored pipes, since the hollow pipe is easily injured by blows, concussions, and the like, thus again giving rise to the inconveniences al ready mentioned. In the hollow pipes, moreover, inflammable and noxious gases or vapors are liable to collect, whereby the conductor is detrimentally affected and shortcircuiting, &c., favored. Nor can these defects be overcome by the use of lead or other cables, as such readily give rise to breakdowns through short-circuiting, grounding, and the like. The outlay involved, moreover, is very great.

The subject of the present invention is an improved means for and a method of insulating electric conductors of whatever crosssection. The new insulator consists of tubular cases or sleeves of a given length filled with an insulating material or composition capable of readily melting, and these filled cases, which will hereinafter be termed can trid ges, are arranged in alinement on the bare conductor or conductors, the whole preferably being then inserted into a protecting-pipe of iron, steel, wood, or the like. To fully fill out the free space with the said material or composition, heat may be applied to the entire pipe for the purpose of melting the insulating composition in the cartridges.

Experiments have already been conducted with a view to laying bare wires in a metallic pipe. Such pipes have been made of lead or iron, and by means of blocks of wood or other non-fusible substances pushed into the pipe the wires have been kept apart, while subsequently the entire system was rendered more stable by pressing in or round it melted insulating composition. For this purpose,

' therefore, special presses and complicated apparatus have been necessary in order that the entire pipe might to some extent be filled out. The insulation, however, has never been perfect, since the insulation in the interior of the pipe cannot be inspected and the individual solid insulating members if lying close together present a small space between them which in the case of the pipe being bent becomes greater and is liable to cause short-circuiting. 1

According to the present invention the row of solid members are themselves capable of being readily melted, so that the pipe can be completely filled. This can be done by means of a simple blow-flame during the work of laying. The safety afforded against fire is consir erable, since even should the steel protecting-pipe become incandescent and the insulating mass melt or boil the bare wire will still be sufficiently insulated. The cartridges of read ily-melting insulating composition, which also act as cistance-pieces, have thus simply to be asembled in alinement and in solid condition inserted into the protecting-pipe.

In order to facilitate pushing of the cartridges over the wires, they may be provided internally with a plurality of tubes of glass, porcelain, or the like, corresponding in number to the number of wires and of such cross-section as exactly to receive the latter. These thin tubes being smooth internally allow of the cartridges being more readily slid on the bare wire.

A further advantage of the invention is that economy can be effected by the employment of a cheap insulating composition in stead of gutta-percha and lead cables, as ordinarily employed. In the case of house installations the conductor can be laid in the plaster between the two ceilings. The conductor is thus effectively protected from the effects of damp and from external mechanical influences, such as blows or shocks, owing to the presence of an external iron or steel protecting-casing and the hardened insulating composition therein.

The invention is shown in the accompanying drawings applied to two conductors.

Figure 1 is a perspective view, and Fig. 1 a plan, of the inner portion of a cartridge. Fig. 2 is a vertical section of a cartridge-case. Fig. 3 is a vertical section of a cartridge, the case being filled with insulating composition. Fig. 3 is a plan thereof. Fig. 4 is an elevaof wire or of the steel piping required. assembled cartridges 1 are pushed. lnto the tion and part section of the cartridge inserted over two bare wires. Fig. 5 shows an as semblage of three cartridges in alinement on the wires. Fig. 6 shows the finished insulating-pipe on the wires, the central portion be ing broken away.

The inner part a of the cartridge preferably consists of two tubes gh, of glass, porcelain, or the like, and a base b. This part ais inserted into a case 0, which may be made of cardboard or like material. Hereupon the space between the tubes g 71. and the case 0 is filled with insulating composition f, capable of readily melting. In this manner the complete cartridge 6 is formed. Such cartridges may have a length of, for example, four inches. The cartridges are then assembled on the wire or wires (1, which maybe stretched to receive them. The number of cartridges employed naturally depends upon the length The protectingpipe e andthe entire pipe then heated, preferably, in upright position. By this means, for which purpose a blow-flame may be used, the insulating composition will be caused to fill the entire inside space. The pipes should be closed at both ends by suitable plugs and may be screw-threaded terminally, as shown at 6, Fig. 6. Connecting or branch pieces or the like suitably filled with the insulating composltlon may naturally also be applied. Ornamental pieces can likewise be added, if desired. The new method admits of any requisite length of in sulation being provided without di'l'l'lculty. In like manner the piping can be readily shortened or divided by cutting through the external pipe and removing the cartridges, so that the bare wire is exposed.

Conductors insulated according to this method are especially adapted for cellars, damp premises, breweries, chemical works, mines, and the like, in which the employment of electric light and power conductors has always been attended with trouble.

WVhat I claim as my invention, and desire to secure by Letters Patent, is

An insulator for electric conductors comprising a series of tubular cases with guiding tubes therein of insulating material for the reception of the conducting-wires, said cases being filled with insulating material surrounding the tubes containing the conductingwires, and being inclosed in aprotecting-pipe, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

STANISLAUS BERGER.

Witnesses:

AnoLF SCH'MALE, CARL GARZ. 

